Respiratory System

The respiratory system consists of several organs responsible for supplying the body with oxygen and removing carbon dioxide out of the body. Oxygen is required by every aspect of the body to function properly. It is brought in the body by the respiratory system and it travels through the circulatory system. Also, releasing carbon dioxide, vital for the body health, is occured by the respiratory system.

There are three main parts of the respiratory system: the airway where air first enters the body and is carried to the lungs, the lungs delivering oxygen to the body and remove waste product carbon dioxide, and the muscles which help expand and contract the lungs to draw air in and out of the lungs.


Breathing starts in mouth and nose where air enters to the body. Air is wetted, warmed and filtered with hairs and mucus membrane in the nose. The mouth has a shorter pathway but it has not hairs and mucus membrane to filter and moisture the air.

The air travels into the throat and then larynx. Throat is also known as pharynx and consists of three parts: the nasopharynx, oropharynx, and laryngopharynx. Larynx is the region where the voice folds are placed.

Air continues through the trachea covered by the epiglottis which makes just the air enter the lungs when a person swallows. The trachea leads the air to lungs. Also, it clears the air from contaminants. The trachea bifurcates to branches known as bronchi.


The bronchi split into thousands of smaller, thinner tubes called bronchioles which branch into alveoli.

The exchange of the gases occurs in the alveoli, then oxygen pass through capillaries around alveoli and is carried to the body parts by them.

Also, capillaries pick up carbon dioxide and send into alveoli. Carbon dioxide passes through the same organs in reverse direction of oxygen.


Diaphragm, intercostal and abdominal muscles contract and expand to pull air into the lungs and to draw air out of the lungs.

The diaphragm is the main muscle in the respiratory system and it is located at between the chest cavity and the abdominal cavity.

When the diaphragm expanding and tightenig, the intercostal muscles between ribs and the abdominal muscles beneath the diaphragm assist.